Bug Description

When creating a new entity, most APIs return a response which includes
"id" to represent a new id. However, only agent API returns "agent_id"
as a new entity. This behavior seems inconsistent from the viewpoint
of whole Nova API.

Change abandoned by Matt Riedemann (<email address hidden>) on branch: master
Review: https://review.openstack.org/292754
Reason: This has had a -1 for awhile now with no reply so I'm considering it abandoned. Please restore and address review comments if you plan on working this.